//
//  ColorHelper.m
//
//  Created by ZhàoYǒng on 23/10/2017.
//  Copyright © 2017 ZhàoYǒng. All rights reserved.
//

#import "ColorHelper.h"

@implementation ColorHelper

UIColor * _Nonnull ColorFromHex(NSInteger color, CGFloat alpha) {
    return [UIColor colorWithRed:((color & 0xFF0000) >> 16)/255.0
                           green:((color & 0xFF00) >> 8)/255.0
                            blue:(color & 0xFF)/255.0
                           alpha:alpha];
}

UIColor * _Nonnull ColorFromString(NSString * _Nullable color) {
    NSString *cString = [[color stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    
    // String should be 6 or 8 characters
    if ([cString length] < 6) {
        return [UIColor clearColor];
    }
    // 判断前缀
    if ([cString hasPrefix:@"0X"])
        cString = [cString substringFromIndex:2];
    if ([cString hasPrefix:@"#"])
        cString = [cString substringFromIndex:1];
    if ([cString length] != 6)
        return [UIColor clearColor];
    // 从六位数值中找到RGB对应的位数并转换
    NSRange range;
    range.location = 0;
    range.length = 2;
    //R、G、B
    NSString *rString = [cString substringWithRange:range];
    range.location = 2;
    NSString *gString = [cString substringWithRange:range];
    range.location = 4;
    NSString *bString = [cString substringWithRange:range];
    // Scan values
    unsigned int r, g, b;
    [[NSScanner scannerWithString:rString] scanHexInt:&r];
    [[NSScanner scannerWithString:gString] scanHexInt:&g];
    [[NSScanner scannerWithString:bString] scanHexInt:&b];
    
    return [UIColor colorWithRed:((float) r / 255.0f) green:((float) g / 255.0f) blue:((float) b / 255.0f) alpha:1.0f];
}

UIColor * _Nonnull ColorFromPoint(CGPoint point, UIView * _Nullable onView) {
    unsigned char pixel[4] = {0};
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(pixel, 1, 1, 8, 4, colorSpace, (uint32_t)kCGImageAlphaPremultipliedLast);
    CGContextTranslateCTM(context, -point.x, -point.y);
    [onView.layer renderInContext:context];
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    UIColor *color = [UIColor colorWithRed:pixel[0]/255.0 green:pixel[1]/255.0 blue:pixel[2]/255.0 alpha:pixel[3]/255.0];
    return color;
}

@end
